Hoshimoto Yoichi, Kinoshita Takuya, Ohashi Masato, Ogoshi Sensuke
Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan).
Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan).
Angew Chem Int Ed Engl. 2015 Sep 28;54(40):11666-71. doi: 10.1002/anie.201505974. Epub 2015 Aug 28.
N-Phosphine oxide substituted imidazolylidenes (PoxIms) have been synthesized and fully characterized. These species can undergo significant changes to the spatial environment surrounding their carbene center through rotation of the phosphine oxide moiety. Either classical Lewis adducts (CLAs) or frustrated Lewis pairs (FLPs) are thus formed with B(C6 F5 )3 depending on the orientation of the phosphine oxide group. A strategy to reactivate FLPs from CLAs by exploiting molecular motions that are responsive to external stimuli has therefore been developed. The reactivation conditions were successfully controlled by tuning the strain in the PoxIm-B(C6 F5 )3 complexes so that reactivation only occurred above ambient temperature.
N-氧化膦取代的咪唑亚基（PoxIms）已被合成并全面表征。这些物种可通过氧化膦部分的旋转，使其卡宾中心周围的空间环境发生显著变化。根据氧化膦基团的取向，由此会与B(C6F5)3形成经典路易斯加合物（CLAs）或受阻路易斯对（FLPs）。因此，已开发出一种通过利用对外部刺激有响应的分子运动来从CLAs中重新激活FLPs的策略。通过调节PoxIm-B(C6F5)3配合物中的应变，成功控制了重新激活条件，使得重新激活仅在环境温度以上发生。
